Vapor-rectifier for high-potential circuits.



J. LE R. HAYDEN: VAPOR RECTIFIER FOR HIGH POTENTIAL CIRCUITS. APPLICATION FILED JUNE 16, 1905.

Patented 0013.28, 1913.

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J. LE R HAYDEN.

EGTIFIER FOR HIGH POTENTIAL CIRCUITS. APPLICATION FILED JUNE 16, 1905.

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Patented 0st. 28, 1913.

UNITED STATES PATENT OFFICE.

JOSEPH LE Roy HAYDEN, or SCHENECTADY, NEW YORK, nssronon TO GENERAL ELECTRIC COMPANY, A oonronn'rron on NEW YORK.

VAPOR-RECTIFIER FOR HIGH-POTENTIAL CIRCUITS.

Specification of Letters Patent. Application filed June 16,

Patented Oct. 28, 1913.

1905. Serial No. 265,600.

To all whom it may concern.

Be it known that I, Josnrn LE ROY HAY- DEN, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Vapor- Rectifiers for lligh-Potential Circuits, of which the following is a specification.

his invention relates broadly to vapor electric devices and more particularly to vapor rectifiers for use on high potential circuits, such for instance as are employed in operating constant current series are lamps.

When vapor rectifiers are operated on high potential circuits they may be subject to a phenomenon which for convenience I prefer to designate by the term arcing or. striking back]? This henomenon may arise from a number of di erent causes and consists in the reversal of the are so that one of the electrodes which normally operates as anode becomes temporarily a cathode. This reverse arc may be only momentary, or it may occur every half Wave for several complete cycles of the alternating current. In either case it introduces an element of instability into the system, and is liable to cause a more or less rapid deterioration of the vacuum by disintegration of the anode or parts adjacent thereto.

Striking back may occur if one of the anodes becomes so hot during operation that a carbon arc can be maintained, in which case thereverse arc takes place to the anode itself. To overcome this tendency I design the rectifier tube so as to avoid an excessive heat at the anode, though for reasons hereinafter pointed out I find it advisable to operate the anode at a considerably higher temperature than the cathode.

A second cause for the phenomenon of striking back is the presence of mercury on the graphite anode or on the platinum lead Wire which connects it to the external circuit. Mercury may be deposited on the graphite anode in several ways, as for instance by spattering or other mechanical projection from the cathode itself, by deposition from an arc containing an excess of vapor, by a cool anode surface, or by a cool space above or beyond the anode in which the mercury vapor may condense and from which it may drop on the anode or into a hotter zone from which it may spatter to the anode.

It is the object of this invention to overcome these difliculties and others hereinafter pointed out and to provide a rectifier suitable for use on veryhigh potentials.

In the drawing, Figure 1 shows one of my nnproved rectifier tubes supplying direct current to a series consumption circuit andreceiving energy 1'' fier tube provided with individual condensmg chambers for the two anodes and with a third condensing chamber located immediately above the cathode; and Fig. 4 shows the anode tubes enter the corresponding condensing chambers from the side.

Fig. l shows one way in-Which I contemplate using my improved form of rectifier tubes, but it should be understood that they may be used in a great variety of ways for converting alternating into direct current. In Fig. l the rectifier 1 is graphite anodes 2 and 3, two mercury odes 4 and 5 anand a mercury cathode 6. The

which I prefer to designate as the cathode chamber. This space connects through a relatively narrow opening with tWo upwardly and outwardly projecting arc tubes 8 and 9 leading toward the corresponding anodes 2 and 3. The anode chambers 10 and 11 which surround the anodes 2 and 3 are made comparatively small in order that no condensation maytake place in the immediate vicinity of the anodes; furthermore, the anodes are located as near as possible to the ends of these chambers so that there is practically no dead space back of the electrodes in which mercury may be condensed and from which it may fall on the anodes. Between the anode chambers 10 and 11 and their corresponding arc tubes 8 and 9 are interposed two bulbs 12 and 13 to serve as condensing chambers for the mer- I cury vapor.

tial is received The tubes upward at 14: and 15 j the condensingchambers giving a comparatively sharp turn for the mercury arc and furnishing a baflie surface for mercury carried mechanically by the arc. Each of the anodes 2 and 3 is connected to a terminal of the movable coil vl6 of transformer 17 and has connected in series therewith one of the reactance coils 18 and 19. The transformer coil 16 is provided with a central tap 20 connected through the series load 21 and a reactance coil 22 to the mercury cathode 6 of the rectifier, The primary 23 of the transformer receives current from a constant potential source 2e. Transformer 17 is of the general type in which alternating current at constant potenat the primary, and in which constant current of varying potential is delivered from the secondary.

To afford, a means for exciting the mercury rectifier, connections are provided from the constant potential source 2 L through a switch 25 to the transformer 26, and the secondar terminals of the transformer are connecte to the auxiliary or starting anodes 4: and 5. A reactance coil 27 is connected directly across this transformer secondary and is provided with a central tap 28 connected through a reactance 29 to the mercury cathode 6/ To start the rectifier, the tube is shaken slightly to establish a momentary contact between the mercury cathode and one of the auxiliary anodes t and 5, thereby allowing current to flow from transformer 26, which 'current, on a subsequent separation of the mercruy surfaces, establishes an arc in the cathode chamber and starts the apparatus. During this starting operation the reactance 29 serves to smooth out irregularities in the current flowing to reactance 27, and assists in prolonging the current flow from the auxiliary anodes, thereby causing a suitable over-lapping of the auxiliary arcs whereby a continuous flow of current to the cathode is obtained. A similar over-lapping of the cur- 8 and 9 are curved ust before entering 12 and 13, thus rent from anodes 2 and 3 is secured by reactances 18, 19 and 22, so that after the rectifier has once been started, the auxiliary anodes may be disconnected from circuit by opening switch 25, though if desired they may be maintained in continuous operation as a safe-guard against unsteadiness arising from serious fluctuations in the consumption circuit.

When the rectifier tube is in normal operation a high velocity blast issues from the surface of the mercury cathode 6 and is projected vertically through the cathode chamher-7 against the wall or bafiie surface 30 of the rectifier tube. Considerable quantities of mercury cathode surface by are carried mechanically from the this blast and conseits projection surface 30 is advantageous in freeing the blast from suspended mercury. Similarly the curved surfaces 1 k and 15' act as baffles for the separation of mechanically suspended mercury so that the blast delivered to the condensing chambers 12 and 13' is comparatively free from it. The large su perficial area of these chambers and their high radiating capacity afford a suitable condensing surface for depriving the mercury blast of all excess mercury and thereby insuring what may be termed a dry blast to the anodes and anode chambers.

When the rectifier is operating under normal conditions, the tubes 8 and 9 show a bright green arc, thus indicating the presence of an excess of mercury vapor, whereas the parts of the rectifier above the condensing chambers show a more reddish looking are similar to the color of a mercury lamp when starting cold and indicating the ab Sence of excess mercury vapor. Special means may be employed for condensing the mercury near the cathode surface, or for preventing the vaporization of the cathode, and in either -case the result is an extension of the range of operation of the rectifier.

To increase the condensation at the cathode I may employ a fan blast directed toward the cathode but shielded from the anodes so that the cathode chamber is considerably cooler than the anode chambers and consequently produces a large part of the total condensation. I make no claim herein to this feature as the same is described and claimed in my copending application, Serial No. 284,333, filed Oct. 25, 1905. To reduce the vaporization at the cathode I may use, instead of mercury, an amalgam containing silver or other refractory metal having a low or substantially negligible vapor tension at the temperature of the mercury arc, as such an amalgam yields mercury vapor with difliculty and so reduces the quantity which must be condensed in the rectifier to enable it to operate with safety on high voltages. The constant vaporization of material from the cathode makes it necessary to provide autoqu ently inatic means for continuously replenishing the cathode material. All the rectifier tubes shown in the drawings are provided with suitable means for performing this important function. When the mercury condenses in the upper parts of the apparatus it flows downward and inward toward the cathode chamber and finally drops into the anode cups at either side of the mercury and these anode cups, overflow into the cathode chamber and keep itfilled with sufficient mercur to cover the platinum lead wire. It is 1m ortant that the mercury should first flow into the anode chambers and then intermittently over-flow into the cathode chamber for if the reverse occurs there is against the glass baflie cathode o the opening 42 danger that the cathode spot will wanden over into an anode chamber when the overflow takes place, and thus introduce part of the exciting circuit in series with the main 5 rectified current.

I have mentioned the factthat mercury may collect on the platinum lead Wires and thereby cause striking back, unless special precautions are taken to prevent such an action. To overcome this ditficulty I employ a novel form of anode and anode connection as shown in detail in Fig. 2. The anode 3 of artificial graphite or other suitable material is of cylindrical form and hollowed out on the inside to decrease the bulk and prevent the retcnsion of occluded gases. The platinum lead Wire 31 which passes through the wall of the rectifier tube is screw threaded centrally in the end of graphite anode 3, but instead, of passing entirely through the end wall of the anode, the end of the wire is completely inclosed by the anode material so that no mercury can be deposited on it. The end of the anode is provided with a cylindrical recess 32 into which tightly fits a lava bushing 33 to completely inclose the platinum Wire where it leaves the graphite anode. In mounting the anode in the tube the blue sealing glass 34, when in a plastic condition, is forced down tight against the upper concave surface of the lava bushing, thus completing the protection for the platinum lead wire, which, as will be seen, is entirely inclosed and consequently protected from amalgamation with the mercury vapor of the arc. The lava bushing 33 is also of value in separating the glass 34 from the anode as I have found that such glass yields a gas when in contact with hot graphite and hence is liable to impair the vacuum of the tube unless special precautions are taken.

The rectifier 35 shown in Fig 3 is somewhat similar to the tube shown in Fig. 1, but the anode condensing chambers 36 and 37 are smaller, and the tube is provided with a third condensing chamber 38 located above the cathode 39. The arc blast issuing from the cathode 39 strikes directly up into the condensing chamber 38 and there loses practically all of the mechanically suspended mercury, as well as partof the excess mercury carried by the arc stream so that the blast which finally finds its way outward through the inclined arms 40 and 41 to enter the chambers 36 and 37 is comparatively dry, or in other words contains little more mercury than is necessary to carry the current of the arc. I find it advisable to make of the central condensing chamber 38 somewhat smaller than the opening 43 of the cathode chamber so that the edges may act as baflie surfaces and so that there is a slight throttling of the cathode 5 blast when it enters the central condensing from sudden variations in the consumptioncircuit or in the source of supply.

I make no claim hereln to the condensing chamber having its lower end constricted so.

as to throttle the cathode blast since this feature is describedand claimed in my copending application, Serial N 0. 284,333, filed Oct. 25, 1905.

The tube shown in Fig. 4 is similar to that shown in Fig. chambers 44 and 45 are provided with a series of bends and enter; the corresponding condensing-chambers 46 and 47 through the side walls so that in case the arc blast is not free from excess mercury when it reaches the condensing chambers 46 and 47 it will:

strike against the ends of these chambers and then be deflected backward and finally find an exit through the sides of the chambers by way of the anode tubes 44 and 45. The reversal of; the direction and the successive turns in the anode tubes completely prevents the deposition of metallic mercury on the anodes or on, the neighboring wall of the tube.

What I claim as new and desire to secure by Letters Patent of the United States, is-

1. A vapor electric apparatus havin a cathode and a plurality of solid anodes, separate tubes for said anodes, and separate condensing chambers connected to said tubes and located directly in the path of arcs to said cathode.

2. A vapor rectifier having a vaporizable cathode, plurality of anodes inclosed in anode tubes, and an enlarged condensing chamber between each anode and said vaporizable cathode and located directly in the path of arcs to said cathode.

3. A vapor rectifier having solid anodes and a vaporizable cathode, a chamber surrounding said cathode, a plurality of arc tubes diverging upwardly from said chamber, a condensing chamber on each arc tube adapted to drain into said cathode chamber, and an anode tube opening into each of said are tubes.

4. A vapor rectifier having a plurality of solid anodes and a vaporizable cathode, separate tubes for said anodes, a condensing chamber operatively related to each of said tubes to protect said anodes from condensed vapor, and means for returning the condensed vapor to the vaporizable cathode.

5. A vapor rectifier having a plurality of' solid anodes and a vaporizable cathode, separate tubes for said anodes, a condensing chamber interposed between each of said anodes and said cathode to protect said anodes from condensed vapor, and means for intermittently replenishing said cathode 3, except that the anodev with condensations from said condensing chamber. V

6. A vapor rectifier having a vaporizable cathode, a condensing chamber arranged immediately above said cathode, a lurality of anodes, and separate con ensing chambers 'operatively related to each of said 7 anodes.

' plurality of anodes,

7. A vapor rectifier having a vaporizable cathode, a condensing chamber arranged to receive the direct blast from said cathode, a

anode tubes surrounding said anodes, and condensing chambers interposed between said anodes cathode. i

8. A vapor rectifier having a vaporizable cathode, a condensing chamber arranged to receive the direct blast from said cathode, a plurality of anodes, a condensing chamber for each anode, anode tubes surrounding said anodes and opening into said condensing chambers, and a bend in each of said anode tubes.

9. A vapor rectifier having anodes and a vaporizable cathode, a chamber, surrounding said cathode, a plurality of arc tubes and said diver ing from said chamer opening into each of said tubes to protect said anodes from condensed vapor, and anode tubes opening into each of said chambers at an'angle to said are tubes.

10. In a vapor electric apparatus, the combination of an evacuated envelop, a lead wire passing therethrough, an electrode mounted on said lead wire, and a lava bushing interposed between said electrode and said envelop.

11. In a va r electric apparatus, the combination 0 an evacuated envelop, a vaporizable electrode therein, a lead wire passing through said envelop, an electrode mounted on said lead wire and completely inclosing the end thereof, and a lava bushing interposed between said electrode and said envelop. y

In Witness whereof, I have hereunto set my hand this 15th day of June, 1905.

J OSEPH LE ROY HAYDEN.

Witnesses:

BENJAMIN B. HULL,

HELEN ORFORD.

chamber, a condensing 

